Pharm Diuretics

Front 1

What is the MOA of a carbonic anhydrase inhibitor? And what can it be used for?

Back 1

Na+ follows bicarbonate- reabsorption. Carbonic anhyrdase can be found in the proximal tubule, CSF and aqueous humor. Therefore, bicarbonate absorption is reduced as well in the aqueous humor (prevents glaucoma) and CSF (therefore, acidosis in the CSF causes hyperventilation to protect against high-altitude sickness).

It is used for Glaucoma, mountain sickness, edema with alkalosis or diuresis in PTs with metabolic alkalosis.

Front 2

Diuretic used for mountain sickness, glaucoma, and edema associated with metabolic alkalosis.

Back 2

Acetazolamide

Front 3

SE of acetazolamide

Back 3

Hyperchloremic metabolic acidosis, paresthesia, sedation, hypokalemia, hyperammonemia in cirrhosis and alkalization of the urine (which may form Ca salts, also prevent conversion of ammonia to ammonium ion in those with liver failure).

Front 4

MOA of loop diuretics?\

What two cations are normally absorbed in the loop of Henle as a consequence of K+ being reabsorbed?

Back 4

inhibits Na+/K+/2Cl- cotransport.

Calcium and Magnesium are absorbed in the thick acending loop from the positive charge (drives Ca and Mg to be absorbed) left in the lumen that set up as K+ is reabsorbed; therefore, furosemide inhibits these two cations.

Front 5

What is the site of action of loop diuretics, and what are some examples? Also, since the prototype is a sulfonamide derivative, what drug can be given to those who are allergic?

Back 5

Thick ascending limb

Furosemide: also bumetanide, torsemide.

Ethacrynic acid can be used for those who are allergic to sulfonaide derivatives and also have the same MOA as furosemide.

Front 6

SE of loop (furosemide) diuretics

Back 6

Since Na+/K+/2Cl- is inhibited, K+ is not reabsorbed, which prevents Ca+ and Mg+ from being reabsorbed. Large amounts of Na presenting to collecting tubule, results in significant potassium wasting and excretion of protons.

Metabolic hypokalemic alkalosis, ototoxicity; hypovolemia, sulfonamide allergy (rare) and hyperuricemia (excess Ca leads to gout).

Front 7

Aminoglycosides used with loop diuretics potentiate adverse effect

Back 7

Ototoxicity

Front 8

Loops lose and thiazide diuretics retain

Back 8

Calcium

Front 9

MOA of thiazide diuretics?

Back 9

Inhibit Na+/Cl- cotransport in the distal convoluted tubule.

Front 10

Site of action of thiazide diuretics

Back 10

Work at early distal convoluted tubule

Front 11

Class of drugs that may cause cross-sensitivity with thiazide and loop diuretics, and some individuals may be allergic to this compound?

Back 11

Thiazide and loop diuretics are sulfonamides

Front 12

SE of thiazide (HCTZ) diuretics

Back 12

Inhibition of Na/Cl increases Na+ to the cortical collecting tubules which tries to reabsorb excess Na for K secretion; therefore, hypokalemia. Lack of intracellular Na promotes Na-Ca exchange at the basolateral side (via parathyroid hormone; Ca is reabsorbed and Na is exchanged for it); therefore, hypercalcemia. Since thiazides work on the diluting segment of the nephron, hyponatremia can occur.

SE: Metabolic hypokalemic alkalosis, hyperglycemia, hyperlipidemia, hyponatremia

Front 13

Potassium sparing diuretics act where and inhibits what? And what are the names of the drugs?

Back 13

They inhibit the Na+/K+ exchange by blocking aldosterone on the principal cell in the collecting tubule (Spironolactone and eplerenone).

Or, they block the epithelial Na channels in the same portion of the nephron (triamterene and amiloride)

Front 14

What diuretic is used to counteract aldosteronism, and what may aldosteronism result from other than Conn's syndrome?

Back 14

Aldosteronism can occur in cirrhosis (lack of metabolism), as well as heart failure (due to decrease cardiac output and renal perfusion).

Spironolactone and eplerenone act as competitive aldosterone receptor antagonist.

Front 15

SE of K+ sparing diuretics?

Back 15

Spironolactone and eplerenone can cause hyperkalemia, gynecomastia (since it acts on androgen receptors, but not eplerenone), and impotence

Front 16

What is mannitol used for and its MOA?

Back 16

MOA: Osmotic diuretic in the proximal tubule and descending limb of Henle's loop.

Osmotic diuretic used for increased intracranial pressure, brain edema with coma, acute glaucoma, solute overload in rhabdomyolysis and hemolysis.

Front 17

What is a carbonic anhydrase inhibitor?

Back 17

Acetazolamide. Others include: dorzolamide and brinzolamide.

Front 18

What are loop diuretics used for?

Back 18

Treatment of edematous states (heart failure, ascites, pulmonary edema) and severe hypercalcemia (must replace volume otherwise, counterintuitive).

Front 19

Effect of prostaglandin on glomerular filtration and NSAIDs

Back 19

Prostaglandin are important for maintaing glomerular filtration. When inhibited by NSAIDs, efficiency of loop and thiazide diuretics decrease.

Front 20

What are the early distal convoluted tubule diuretics and their clinical use?

Back 20

Thiazide diuretic, and hydrochlorothiazide is the prototype.

They are used for hypertension and chronic renal calcium stone formation (since they can reduce Ca concentration in the urine). They can help with chronic therapy edematous conditions, but loop diuretics are preferred.

Front 21

What is the drug that is mainly used for edematous conditions (e.g., heart failure, pulmonary edema) and for a different drug for hypertension?

Back 21

Edematous states: loop diuretics

Hypertension: thiazide diuretics.

Front 22

SE of mannitol?

Back 22

Headache, nausea, vomiting, dehydration.

Front 23

What are two ADH agonists and their MOA?

What are they used for?

Back 23

ADH, vasopressin or desmopression can facilitate water reabsorption form the collecting tubule by activation of V2 receptors, which stimulate adenylyl cyclase via Gs. Increase in cAMP results in insertion in additional aquaporin AQP2 water channels.

They are used for diabetes insipidus.

Front 24

Small cell carcinoma of the lung can cause what, and what drug can counteract this?

Back 24

Can produce ectopic production of ADH, resulting in syndrome of inappropriate ADH secretion (SIADH).

Conivaptan is an ADH antagonist that can be used. It can also be used for hyponatremia. Demeclocycline, a tetracycline can also be used.

Front 25

What is the SE of conivaptan?

Back 25

When treating SIADH, it may cause demyelination with serious neurologic consequences if hyponatremia is corrected too rapidly.

Front 26

A 70 year old man is admitted with a history of recurrent heart failure and metabolic derangements. He has marked peripheral edema and metabolic alkalosis. What is the most appropriate treatment for his edema?

Back 26

Acetazolamide, a carbonic anhydrase inhibitor.

Front 27

A 50 year old man has a history of frequent episodes of renal colic with calcium-containing renal stones. A careful workup indicates that he has a defect in proximal tubular calcium reabsorption, which results in high concentrations of Ca salts in the tubular urine. The most useful diuretic agent to treat recurrent Ca stones is?

Back 27

Hydrochlorothiazide, a thiazide.

Front 28

What is a important effect of chronic therapy with loop diuretics?

Back 28

Increase in urinary calcium, metabolic alkalosis, and ototoxicity.

Front 29

A PT with long-standing diabetic renal disease and hyperkalemia and recent onset mild heart failure requires a diuretic. Which of the following agents would be the safest in a PT with severe hyperkalemia?

Back 29

Hydrochlorothiazide, a thiazide.

Front 30

Which of the following diuretics would be most useful in the acute treatment of a comatose PT with brain injury and cerebral edema?

Back 30

Mannitol

Front 31

A 60 year old PT complains of paresthesias and occasional nausea associated with one of her drugs. She is found to have hyperchloremic metabolic acidosis. She is probably taking?

Back 31

Paresthesias and GI distress are common adverse effects of acetazolamide, especially when taken chronically for glaucoma.

Front 32

A 70 year old PT is admitted to the ED because of a "fainting spell" at home. She appears to have suffered no trauma from her fall, but her blood pressure is 120/60 when lying down and 60/20 when she sits up. ECG are within normal limits when lying down. She has taken "water pills" (diuretics) for a heart condition. What drug most likely will cause the fainting spell?

Back 32

Syncope (fainting) is associated with this PTs history. Arrhthmias are due to excessive potassium loss. Although K+ is more common with thiazides (due to their long duration of action), they rarely cause reduction of blood volume this sufficient.

Answer: furosemide, a loop diuretic.

Front 33

A 55 year old PT with hypertension and mild heart failure is started on a thiazide diuretic drug. Two days later, he has a seizure and is brought to the ED in a comatose state. Blood report for electrolyte analysis may indicate?

Back 33

Since thiazides work in the diluting segment of the nephron (distal convoluted tubule), they may reduce the excretion of water and cause dilutional hyponatremia. This can cause fatal CNS toxicity, especially if drinking lots of water.

Front 34

A drug that has its major effect in the proximal tubule, descending limb of the loop of Henle, and the cortical collecting duct is?

Back 34

Mannitol

Front 35

A drug that increases the formation of dilute urine in water-loaded subjects and is used to treat SIADH is?

Back 35

Conivaptan, a ADH antagonists.

Front 36

A drug that is useful in acute glaucoma and high-altitude sickness is?

Back 36

Acetazolamide.

Front 37

What therapy will be most useful in the management of severe hypercalcemia?

Back 37

Furosemide, a loop diuretic, plus saline infusion (to not reduce blood volume which would not decrease calcium alone)

Front 38

What is thiazides affect on calcium?

Back 38

They produce hypocalciuria (by reabsorption of calcium--hypercalcemia) and can be used to treat calcium kidney stones.